For those who do not know, California has banned the use of Lead in ammunition used for hunting. Why? Supposedly to reduce toxicity in birds eating lead lumps and shot. In reality, more likely IMHO is that the goal was to make it harder to get any ammo to shoot and raise prices.
The result has been a lot of use of Bismuth in shot as the weight is about the same as lead and it is non-toxic. Also it isn’t that expensive. For hunting rounds in rifles, the use of solid copper and related alloys has been common.